overhaul ci config & remove some separate-repo cruft

Author: alexcjohnson

.circleci/config.yml

@@ -1,3 +1,3 @@
 # These owners will be the default owners for everything in
 # the repo. Unless a later match takes precedence
-* @alexcjohnson @Marc-Andre-Rivet @rpkyle
+* @alexcjohnson

.github/CODEOWNERS

@@ -15,7 +15,7 @@
     "private::format.black": "black dash_core_components_base/ tests/ setup.py",
     "private::format.eslint": "eslint src --fix",
     "private::format.prettier": "prettier --config .prettierrc --write src/**/*.js",
-    "private::lint.black": "if [ \"$PYTHON_VERSION\" != \"py27\" ]; then black --check dash_core_components_base/ tests/ setup.py; fi",
+    "private::lint.black": "black --check dash_core_components_base/ tests/ setup.py",
     "private::lint.eslint": "eslint src",
     "private::lint.flake8": "flake8 --exclude=dash_core_components,node_modules,venv",
     "private::lint.prettier": "prettier --config .prettierrc src/**/*.js --list-different",